354 CoL Beaufoy*s Astronomical Observations, [NoV, 



marsupium is destined to perform the office of a second, I was 

 going to say a more important, uterus ; just at the time when 

 the first litter have attained such a size, that they are no longer 

 (one or two of them at the utmost) capable of taking refuge in 

 her pouch ; and when, being now provided with teeth, and the 

 requisite strength^ they are not necessarily/ dependant upon their 

 mother. 



But even after the second litter has been received into the 

 marsupium, the young of the first litter, if any of them be living, 

 still continue with the mother, who does not yet withdraw from 

 them her useful attentions and assistance. They are no longer 

 indeed permitted to take the milk secreted by her breasts ; but 

 she sedulously watches them, and even conveys them, while they 

 cling to her back and tail, for considerable distances through the 

 woods, $cc. 



But it is time to put an end to this long letter. Believe me, 

 I shall be truly glad if it afford you any information or amuse- 

 ment. 



With the genuine regard of a naturalist, I remain, my dear 

 Sir, your friend, &c. Benjamin Smith Barton. 



Article VI. 



Astronomical Observations ^ 1823. 

 By Col. Beaufoy, FRS. 



Bushey Heath, near Stanmore, 



Latitude 51° 37' 44*3" North, Longitude West in time I' 20'93", 



Oct 2. Immersion of Jupiter's second ^ IS** 11' 7" Mean Time at Busliey. 



satellite C 12 12 28 Mean Time at Greenwich. 



Oct, 2. Immersion of Jupiter's first ^17 26 57 Mean Time at Bushey. 



satellite ( 17 28 18 Mean Time at Greenwich. 



Oct. 9. Immersion of Jupiter's second < 1 4 47 28 Mean Time at Bushey. 



satellite I 14 48 49 Mean Time at Greenwich. 



Oct. 11. Immersion of Jupiter's first J 13 48 38 Mean Time at Bushey, 



satellite ( 13 49 59 INIcan Time at Greenwich. 



Immersion of Jupiter's first \ ^"^ 23 27 Mean Time at Busliey. 

 satellite l 17 24 48 Mean Time at Greenwich. 



we compare this first gestation with that of the marsupium. But I have shown, that 

 the female didelphis carries her young in utero between twenty- two and twenty-six days, 

 which is no inconsiderable period, if we reflect on the very small size (sometimes lesa 

 than one grain) of the cmbryons, when they are dislodged from the uterus : for the 

 weight of our female opossum is often, at least, 1 8 lbs. 





